Energy properties of Eucalyptus benthamii wood based on tree age and region in Guarapuava, Paraná state, Brazil

This study aimed to evaluate the properties of Eucalyptus benthamii wood for bioenergy purposes. Trees were sampled in five diametric classes and used to evaluate properties of the wood according to three ages (5, 6 and 7 years) in three regions of E. benthamii production in Parana state, southern Brazil. The basic density, proximate analysis, gross calorific value and net calorific value, and energy density were determined. For evaluation of the energy properties, 27 composite samples were used, which represented tree classes of minimum, medium and maximum diameter. The variables were statistically analysed under the effect of tree age and region. Basic density was positively affected by age, and this effect was reflected in energy density of the wood. The interaction of Region 1 with trees of age seven years identified the best conditions for biomass energy production from this source. As there were no significant differences in the immediate chemical analysis and the calorific value for either factor evaluated, we suggest that plantation managers could reduce the cutting cycle without compromising the energy efficiency of these forests.